The Piper Aerostar (formerly the Ted Smith Aerostar) is an American twin-engined propeller-driven executive or light transport aircraft, designed by Ted R. Smith. It was originally built by Ted Smith Aircraft Company, but the design was acquired in 1978 by the Piper Aircraft Corporation, which continued production of the aircraft as the PA-60.
After having designed the Aero Commander and Jet Commander, Ted R. Smith founded the Ted Smith Aircraft Company in 1963 to build a new line of aircraft. The first Aerostar prototype, the Model 320, was built with two 160hp Lycoming IO-320 engines and first flew in November 1966. The same aircraft was upgraded with a pair of 180hp Lycoming IO-360 engines and a more streamlined vertical fin and renamed the Model 360; it was subsequently upgraded again with 200hp IO-360s and renamed again as the Model 400. The aircraft finally entered production as the Aerostar 600 with two 290hp Lycoming IO-540-K engines, first flown in December 1967. Also produced, and the base of most of the subsequent models, was a version with turbocharged engines, the Aerostar 601.
The aircraft were originally built at Van Nuys, California, but in 1968 the company was bought by the American Cement Company. The acquisition was not a success, and in 1969 the company was sold again to Butler Aviation, a major fixed base operator and owners of Mooney Airplane Company. The new company was renamed Aerostar Aircraft Corporation, and plans were made to move production to the Mooney plant at Kerrville, Texas, but this did not occur because Butler got into a dispute with American Cement regarding alleged corrosion problems with the airframe; the U.S. Federal Aviation Administration (FAA) investigated and found that no such problem existed, but the dispute resulted in a two-year production hiatus. In 1971, Smith attempted to repurchase the rights and announced he would be building an all-new design that was better than the Aerostar, but negotiations broke down.[1] The Bellanca Aircraft Company and Chance Vought also expressed interest in acquiring the design.
In 1972, Ted Smith successfully bought back all the rights to the aircraft and began manufacturing Aerostars under the Ted R. Smith and Associates banner in Santa Maria, California, introducing the pressurized Aerostar 601P along with the Aerostar 700 Superstar. In 1976, the company name was changed to the Ted Smith Aerostar Corporation. 1974 saw the introduction of the successful 601P, which introduced cabin pressurization, allowing more convenient high-altitude operation; the designers were able to adapt the fuselage to pressurization without having to limit its service life. The 601P and the 601B, which was introduced in 1977, both feature improvements to the turbocharging system and a 2.5feet greater wingspan, increasing climb rates and making the engines more reliable and easier to operate.
Smith died suddenly in 1976.[2] In 1978, the Aerostar line was acquired by the Piper Aircraft Corporation, which continued to build two variants, the 600A and 601B, and then re-introduced the 601P. Piper continued using the basic Ted Smith model designation system but prefixed each model as the PA-60. Piper introduced the enhanced 602P, which was initially marketed as the Sequoya, and also put the 700 Superstar into production as the 700P. The 602P was the first model with a turbocharger system built and certified by the engine manufacturer, rather than a turbo system designed and installed by Ted Smith or Piper. After discontinuing production of the non-pressurized models, Piper moved production to Vero Beach, Florida, building the last Aerostar there in 1984.[2]
Smith conducted engineering studies for a jet-powered Aerostar, and also envisioned turboprop power and a single-engine trainer aircraft using the same basic airframe, but these plans never came to fruition during the aircraft's production run.[2] [3]
The Aerostar emerged as a mid-wing cantilever monoplane powered by two wing-mounted piston engines, with retractable landing gear in a tricycle configuration. It is designed to seat six, and is distinguished from light twins of similar size and weight by its high wing loading, careful attention to fine aerodynamic details, a mid wing, and in early models, the absence of cowl flaps; Smith was adamant that they were not needed because of the refined cooling system design. Despite this, the later 700P used cowl flaps because engine cooling of earlier models proved marginal if the system is not maintained rigorously.[4]
The engines of early 601s are turbonormalized—they retain the higher compression ratio typical of a non-turbocharged engine, and the turbo system is designed to primarily to compensate for increasing altitude by providing more boost pressure as the outside air pressure declines. Later models featured a redesigned turbo system intended to increase reliability and be more forgiving of improper operation by the pilot.[4] Unusual Aerostar design features include electrically operated remote fuel valves, which avert the need to run fuel lines into the cockpit; electro-hydraulic nosewheel steering; a flight control system that relies on push-pull rods and torque tubes rather than cables; and unusually thick and stiff wing skins, which—together with the high wing loading—give the Aerostar an unusually smooth ride in turbulence.[3] [4]
Some disadvantages of the aircraft compared to its competitors are the absence of a nose baggage locker, and a cabin that can only be accessed through a single clamshell door next to the pilot's seat; aircraft occupants other than the pilot in command must climb over the folded pilot's seat to access their seats.[4]
Aerostar model numbers nominally refer to the total installed engine horsepower, but some model numbers vary from the precise total, particularly the later models.
During the time of production, the Aerostar held the speed record for fastest twin piston general aviation aircraft,[5] capable of cruise speeds from for the earliest 600 models to for the later 700 models. Light construction, low drag, and powerful engines contribute to fast climb rates, while allowing high operating altitudes and class-leading fuel efficiency.[4]
A study of Aerostar accidents by The Aviation Consumer from 1978 to 1982 showed that the Aerostar had an accident rate of 12.9 per 100,000 flight hours, substantially more than the rate of the comparable Beechcraft Baron 58 at 4.9 per 100,000 hours. A similar study conducted by Aviation Safety compared the safety records of eight similar models of twin-piston-engine aircraft and found that the Aerostar had the highest accident and fatal accident rate. According to the studies, the leading cause of Aerostar accidents was engine failures on takeoff. The Aviation Consumer notes that the Aerostar's high wing loading, which contributes to its high cruise speed, also gives it relatively unforgiving flying qualities on takeoff and landing; the aircraft requires relatively long runways, and pilots must keep the airspeed high during approach to avoid falling behind the power curve, which can cause an excessive sink rate. The wing flaps of the Aerostar slow the aircraft relatively quickly, which may induce this problem, so pilots typically do not use the full 20-degree flap setting until the aircraft is close enough to the runway to ensure a safe landing.[3]
The Aerostar has a history of accidents stemming from fuel mismanagement by the pilot.[3] Most later Aerostars have a 41.5gal fuselage fuel tank and individual 62gal fuel tanks in each wing, which all feed into a common chamber near the fuselage tank; the common chamber in turn normally feeds the engines. However, the relative lack of wing dihedral may cause the wing tanks to feed unevenly when used in this manner, causing a fuel imbalance as flight progresses. This problem can be mitigated by using the fuel valves to crossfeed fuel from one wing tank to the opposite engine, bypassing the common chamber; however, the wing tanks are prone to unporting when they are mostly empty, causing engines to lose power or stop running. This hazard can be exacerbated if electrical power is lost, as the electrically operated fuel valves will become inoperable, preventing the pilot from switching back to the fuselage tank. To mitigate these problems, a 1984 airworthiness directive (AD) required owners to install individual, more accurate fuel gauges for each wing tank, a dedicated low-fuel warning light, and placards explaining correct crossfeed procedures.[3] [4]
The Aerostar has a history of problems with the clamshell-style entry door, which is located directly in front of the left-hand propeller, making it critical for the door to be secured before takeoff. A number of accidents have resulted from the upper half of the door coming open in flight and in some cases separating from the aircraft. Although it was not conclusively listed as causal, an unsecured upper door is widely thought to have contributed to a 1988 crash that killed pilot and auto racing driver Al Holbert.[3] That year, the FAA issued an AD requiring inspection of the door rigging, a placard explaining proper door operation, and a dedicated door-ajar warning light. In addition, the FAA has issued warnings regarding an aftermarket door strut which required an installation procedure that may damage a door gusset; the gusset may break in flight and cause the door seal to fail, potentially causing uncontrolled decompression in pressurized versions of the Aerostar.[3]
Although nominally a six-seat aircraft, owners often remove center-row seats because most Aerostars have inadequate payload to simultaneously carry six people, their baggage, and a large fuel load, and removing the seats improves access and legroom in the third-row seats, which are quieter than the other seating positions and are therefore preferred by many passengers.[3] [4]
The Aerostar has a reputation for high maintenance requirements and servicing costs due to a cooling system design that is intolerant of poor maintenance, a lack of working space around various aircraft systems, and a turbo system that is sensitive to exhaust system problems.[3] [4]
The Aerostar type certificate and manufacturing documentation were sold in 1991 to former Ted Smith Aerostar employees Jim Christy and Steve Speer, who operate Aerostar Aircraft Corporation (originally Machen Incorporated[3]), providing maintenance and support for the aircraft and continued research and development.[4] [2] [6] In 2006, Speer restarted design studies for a jet-powered Aerostar, and in 2010, Aerostar Aircraft first flew the Aerostar Jet, a 601P refitted with a pair of wing-mounted Pratt & Whitney CW615F engines, providing an estimated maximum cruise speed of . In 2014, Aerostar Aircraft said it was investigating production of the aircraft.[2]